package org.neo4j.index.lucene;
import java.util.Collection;
import java.util.HashSet;
import java.util.Iterator;
import java.util.Set;
import org.apache.lucene.document.Document;
import org.neo4j.helpers.collection.PrefetchingIterator;
class DocToIdIterator extends PrefetchingIterator<Long>
{
private final Iterator<Document> docs;
private final Collection<Long> exclude;
private final IndexSearcherRef searcherOrNull;
private final Set<Long> alreadyReturnedIds = new HashSet<Long>();
DocToIdIterator( Iterator<Document> docs, Collection<Long> exclude,
IndexSearcherRef searcherOrNull )
{
this.docs = docs;
this.exclude = exclude;
this.searcherOrNull = searcherOrNull;
}
@Override
protected Long fetchNextOrNull()
{
Long result = null;
while ( result == null )
{
if ( !docs.hasNext() )
{
endReached();
break;
}
Document doc = docs.next();
long id = Long.parseLong(
doc.getField( LuceneIndexService.DOC_ID_KEY ).stringValue() );
if ( exclude == null || !exclude.contains( id ) )
{
if ( alreadyReturnedIds.add( id ) )
{
result = id;
}
}
}
return result;
}
private void endReached()
{
if ( this.searcherOrNull != null )
{
this.searcherOrNull.closeStrict();
}
}
public int size()
{
return ( ( HitsIterator ) this.docs ).size();
}
}